1. Field of the Invention
The present invention is related to a ski, especially an alpine ski, a monoski or a snowboard. It is particularly related to an improvement in this type of ski.
2. Discussion of Background and Relevant Information
Skis that are in general use comprise a lower sliding surface that connects two lateral surfaces along two lower edges provided with metallic running edges, the lateral surfaces connecting an upper surface. The skis have a relatively small width with respect to their length, their front end being curved upwardly to form a spatula. The thickness of the ski is generally greater in the central portion than in the front and rear portions of the ski. In the most commonly used classic shapes, the width of the lower surface of the ski is smaller in the central portion than in the rear and front portions, the width being maximum at the front portion of the ski, i.e., in the vicinity of the spatula.
In known ski structures, the upper surface of the ski is generally a regulated surface, i.e., defined by the longitudinal displacement of a transverse straight line parallel to the lower surface of the ski. In other words, the transverse section of the ski is generally a rectangle or a trapezium, the larger opposing sides of the rectangle or of the trapezium being formed by the lower surface and the upper surface of the ski, the smaller opposing sides of the rectangle or of the trapezium being formed by the lateral surfaces of the ski.
The greater thickness of the ski in the central zone confers a greater rigidity to the central zone. Such central zone is also adapted to receive the bindings for the adaptation of a boot of the user. On the other hand, the front and rear zones of the ski, which have a reduced thickness, are more flexible and become deformed elastically during use of the ski. If one wishes to obtain a ski with a good flexibility in the front and rear zones, it becomes necessary to provide such front and rear zones with reduced thicknesses.
A first problem encountered in traditional ski structures is that the central zone of the ski, which has a relatively substantial thickness in order to provide it with greater rigidity, causes a fairly substantial spacing of the bindings with respect to the lower edges of the ski. The lower edges are elements which are adapted to bite into the ice, while taking a turn. The efficiency of the lower edges provided with running edges is that much better when the connection between the foot of the user and the running edge is more direct. The spacing between the running edge and the binding tends to decrease the efficiency of the running edges. To overcome this disadvantage, European Patent Application No. 465,794 describes a ski structure having, especially on its upper surface, a median rib extending longitudinally on either side of the central zone and lowered lateral recesses bordering each side of such rib and on which a support or a stirrup in the shape of an inverted "U" takes support, the element adapted to receive the bindings.
A second problem encountered in current ski structures is that in some configurations, especially when the skier is leaning forward while entering a curve or, conversely, leaning backward, while leaving a curve, the portion across from the support becomes lighter and loses contact with the snow. To respond to this problem, French Patent Application Nos. 9,016,048, 9,105,012 and 9,204,190, for example, suggest replacing the median rib by an attached element, made of one or two portions constituting a stiffener, partially linked to a base and which extends longitudinally, at least in the central zone of the ski and advantageously beyond it, i.e., along a length comprised between approximately 50 and 80 percent of the length of the base in contact with the snow. The stiffener enables a balanced distribution of pressures of the ski in movement to be obtained and also enables the above-cited disadvantages of traditional skis to be avoided, whatever the configuration of the skier. Thus, the ski gains in stability and according to the adjustment of the stiffener and/or its design, the stability/maneuverability ratio can be improved.